Bistable reciprocable switch construction

ABSTRACT

A reciprocable switch comprises a contact carrier movable to either of two operating positions in response to a cycle of operation of a pushbutton and in which the carrier is stable in either of its two positions. The carrier is coupled to a oscillatory actuator which is rockable between two extreme positions. The actuator supports an index slide which is straddled by indexing barbs carried by the pushbutton, engagement of the slide by one barb effecting rocking of the actuator from one position to the other. A spring urges the pushbutton to a normal position, maintains the carrier and the actuator in stable positions, and effects shifting of the slide from a position in which it is engageable by one of the indexing barbs to a position in which it is engageable by another of the indexing barbs. The parts of the switch are contained in a casing which removably may be fitted to a support on which the fixed contacts are mounted.

United States Patent 2,285,916 6/1942 Eisner 3,04 ,377 7/1962 FraserWilliam F. Swisher St. Clair Shores, Mich. 821,292

May- 2, 1969 June 22, 1971 Essex International, Inc. Fort Wayne, 1nd.

lnventor Appl. No. Filed Patented Assignee I ReferenocsCited UNITEDSTATES PATENTS ZOO/153.9

3,229,053 l/l966 Smith. 200/166PCX Primary Examiner-Robert K. SchaeferAssistant ExaminerWilliam J. Smith Attorney-Leannan and McCullochABSTRACT: A reciprocable switch comprises a contact carrier movable .toeither of two operating positions in response to a cycle of operation ofa pushbutton and in which the carrier is stable in either of its twopositions. The carrier is coupled to a oscillatory actuator which isrockable between two extreme positions. The actuator supports an indexslide which is straddled by indexing barbs carried by the pushbutton,engagement of the slide by one barb efi'ecting rocking of the actuatorfrom one position to the other. A spring urges the pushbutton to anormal position, maintains the carrier and the actuator in stablepositions, and effects shifting of the slide from a position in which itis engageable by one of the indexing barbs to a position in which it isengageable by another of the indexing barbs. The parts of the switch arecontained in a casing which removably may be fitted to a support onwhich the fixed contacts are mounted.

\\\\\\\A\\\\\\ ,rfi 5 1 II I, 1- 4 29' l I 3CD t is PATENTEDJUNZZISH3,586,806

sum 1 or 2 I 39 2, 4O WILLIAM F. SWISHER FIG. 3 BY Mv-WW makes or breaksa circuit, and return movement of the operatort'o its projected positioneither breaks or makes such circuitfiln the other kind of knownpushbutton switch, the operatio'n'is the same as that just described,but the operator may be provided with means for latching it in itsretracted position so as toi'naintain the movable contacts in a selectedposition corresponding substantially to that which they occupy when theoperator is in its retracted position. In most switches of the latterconstruction, the latching means is effective only in response topartial return movement of the operator to its retracted position. Insuch constructions, the force applied on the movable contacts tomaintain them in the selected position thus is less than that which isapplied to them when the operator is in its fully retracted position. Itis possible, therefore, that the decrease in force will permit somelooseness or undesirable instability of the movable contacts, which mayresult in arcing or pitting of the contacts.

Pushbutton switches in general use heretofore usually have beenself-contained in the sense that the movable and fixed contacts aresupported within the same casing. There are many instances, however,especially in constructions utilizing printed or integrated circuits,when the fixed contacts are carried by a substrate or base. In suchconstructions switching can be effected by the provision of movablecontact means only if they are associated with and properly oriented tothe substrate and to the fixed conductors supported thereby.

An object of this invention is to provide a pushbutton operated switchhaving a contact carrier movable between two positions in either ofwhich the carrier is maintained in an equally stable condition.

Another object of the invention is to provide a pushbuttonoperatedswitch wherein the indexing of the contact carrier from one position tothe other is effected by positive engagement between indexing means,rather than by reliance upon springs or other resilient means.

A further object of the invention is to provide a switch of thecharacter described and wherein a single spring controls the pushbuttonoperator and the indexing means, and yieldably biases the contactcarrier so as to maintain the latter in the position to which it hasbeen moved.

Another object of the invention is to provide a pushbuttonoperatedswitch provided with means for separably mounting it in an operativeposition on a support for fixed contacts.

Other objects and advantages of the invention will be I pointed outspecifically or will become apparent from the following description whenit is considered in conjunction with the appended claims and theaccompanying drawings, in which:

FIG. 1 is an isometric view of an assembled switch constructed inaccordance with the invention;

FIG. 2 is an enlarged, transverse sectional view of the switch andillustrating the contact carrier in one of its two positions ofadjustment;

FIG. 3 is a view similar to FIG. 2, but illustrating the contact carrierin its other position of adjustment;

FIG. 4 is a sectional view taken on the line 4-4 of FIG. 2, but with thepower spring omitted; and

FIG. 5 is a sectional view taken on the line 5-5 of FIG. 4. A switchconstructed according to the invention comprises a casing 1 formed ofnonconductive material having parallel sidewalls 2 and parallel endwalls 3 defining a chamber 4 open at both its top and bottom. Within thechamber 4 is an actuator body 5 formed of nonconductive material havinga depressed, flat center section 6 terminating at its opposite ends inupwardly diverging walls 7 which, in turn, tenninate in vertical walls8. At the upper end of each wall 8 is a stub shaft 9 that is rotatablyaccommodated in an opening 10 formed in the adjacent casing wall 2 so asto mount the body 5 for rocking or oscillating movement about the axesof the shafts 9.

Spanning the distance between the walls 2, and parallel to the walls 3is a pair of spaced apart rails 2a. The rails straddle the body 5 andserve to limit the extent to which the body 5 may be rocked ineitherdirection.

A contact carrier is coupled to the body 5 for back and forthreciprocating movements in response to oscillation of the body. Thecarrier 11 comprises a generally U-shaped, conductivemember having a web12 terminating at each end in an upstanding flange 13 which isvertically slotted as at 14 for the pivotal accommodation of studs 15carried by the body walls 8. Button contacts 16 are fixed to and projectfrom the web 12.

The slots 14 are substantially greater in length than the diameter ofthe studs 15 so as to provide for limited lost motion between the body 5and the carrier 11. The opposite ends of the carrier web 12 are deformedto form spring tongues 17 which bear against the studs 15 and constantlybias the carrier 11 downwardly, as viewed in FIG. 5.

Slideably accommodated in the body 5 is an indexing slide 18 ofgenerally cup-shaped configuration having a bottom 19 and four upwardlydiverging sidewalls 20. The slope of the walls 20 correspondssubstantially to the slope of the two walls 7 of the body 5 so as toenable the slide 18 to nest in the body with the bottom 19 slideablysupported on the center section 6. The rails 2a are so located as to liein the path of sliding movement of the slide 18 and limit the extentto'which the latter can move relatively to the body 5.

The upperend of each sidewall 20 terminates in a laterally extendingflange 22 that slideably is accommodated in a groove 23 formed in theupper end of the adjacent wall 8. The upper end of each leg 8 has aflange 24 that overhangs the associated groove 23. Each end wall 21 ofthe slide member terminates in a projecting tongue 25, the upper surface26 of which is inclined outwardly and downwardly of the slide member.

A pushbutton operator 27 is included and comprises a fingerpiece 28provided at two of its opposite sides with depending legs 29 T-shaped incross section and which are slideably accommodated in correspondinglyshaped guide grooves 30 formedin the end walls 3 of the casing 1. Eachend wall 3 has an inwardly extending enlargement 3a through which the associated leg 29 projects. The free end of each leg 29 terminates in anindexing or driving barb 31 which projects into the casing chamber 4.Each barb 31 has lateral extensions 31a which may abut the lower end ofthe adjacent enlargement 3a.

The operator 27 is reciprocable from a normal position indicated in fulllines in FIG. 2 to a retraced position within the casing 1, as indicatedin dotted lines in FIG. 2, and is biased toward its normal, projectedposition by a conical power spring 32, one end of which seats on aspring retainer 33 carried by the fingerpiece 28. The opposite end ofthe spring 32 hasa rounded end 34 which is accommodated in a groove 35formed in the bottom 19 of the index slide 18. Inward or retractingmovement of the operator 27 is limited by abutments 36 on each wall 3and lying in the path of movement of the legs 29.

The disclosed construction is especially adapted for use in conjunctionwith printed circuitsand the like in which fixed, conductive strips 37are supported on a suitable substrate or base 38. The casing 1, togetherwith all of the parts contained therein, may be removably assembled withthe base 38 by means of flexible, attaching lugs 39 which extend inprolongation of the casing end walls 3 and which may be accommodated inopenings 40 formed in the base 38. Thelugs 39 preferably have latchingbarbs 41 at their free ends for engagement with the under surface of thebase 38, the lugs 39 being sufficiently flexible to enable the barbs tobe disengaged and permit disassembly of the casing from the base. Thelength of the lugs 39 should be sufficient to pass through the base 38and permit the contacts 16 on the carrier 11 to make engagement with thefixed contacts 37 in all positions of the carrier 11. The location andvertical height of the abutmcnts 36 accomplishes this objective,together with the lost motion coupling of the carrier 11 to the body 5,in conjunction with the spring fingers 17.

When the casing 1 is in assembled relation with the base 38, asindicated in FIG. 2, the spring 32 will maintain the operator 27 in itsprojected position, the engagement of the barb extensions 310 with theenlargements 3a limiting outward movement of the operator. The spring 32also exerts a force on the body 5 tending to rock it counterclockwisefrom the position shown in FIG. 2, but the engagement of the body 5 withthe left-hand rail 20 prevents such rocking of the body. The carrier 11thus is forcibly, but yieldably, maintained at one end of its path ofmovement. The force exerted by the spring 32 also urges the indexingslide 18 downwardly and toward the left from the position shown in FIG.2 and in which the left-hand tongue 25 overhangs the associated end ofthe body 5. The engagement of the slide 18 with the left-hand rail 2a,however, precludes any movement of the slide 18 to the left from theposition shown in FIG. 2.

Upon a retracting or inward stroke of the member 27, the legs 29 willmove from the positions shown in full lines in FIG. 2 to the positionsshown in dotted lines. The left-hand indexing barb 31 will engage theleft-hand tongue 25 of the slide 18, the inclined surface 26 enablingthe indexing barb 31 to cam or shift the slide 18 to the right, againstthe bias of the spring 32. When the barb 31 disengages the tongue 25,the spring 32 will return the slide to the left, whereupon the tongue 25will overhang the barb 31. Upon release of the operator 27, the spring32 will move the latter upwardly on its return stroke, whereupon theleft'hand indexing barb 31 will engage the overhanging tongue 25 androck the body 5 clockwise about the axis of the shafts 9. Theindexingparts 25 and 31 will remain in engagement until the body has been rockedclockwise to aposition in which it is inclined toward the opposite sideof the casing, whereupon the spring 32 will rock the body to its otherextreme position in engagement with the right-hand rail 20, as shown inFIG. 3, and simultaneously shift the slide 18 to the right intoengagement with the rail and locate the right-hand indexing tongue 25 inthe pathof movement of the right-hand indexing barb 31. Such movement ofthe slide 18 does not take place, however, until after the operator 27has traversed a distance on its return stroke sufficient to enable theright-hand indexing barb 31 to be clear of the path of movement of theassociated indexing tab 25.

As the actuator body rocks clockwise from the position shown in FIG. 2to the position shown in FIG. 3, the carrier 11 will move from one endof the casing toward the other, whereupon the contacts 16 will engagedifferent ones of the fixed contacts 37. During movement of the carrierthe spring fingers 17 will deflect, as required, to enable the posts tomove longitudinally of the slots 14.

The carrier 11 may be returned to its initial position from the positionshown in FIG. 3 upon the retraction of the operator 27 into the casing la distance sufi'rcient to locate the righthand indexing barb 31 beneaththe right-hand indexing tongue 25, whereupon the return stroke of theoperator will rock the body 5 counterclockwise from the position shownin FIG. 3 to the position shown in FIG. 2. Thus, the operator 27 movesfrom and to its normal or projected position upon sequential strokesthereof, but the carrier 12 is shifted from one position to another onalternate strokes of the operator.

The disclosed embodiment is representative of a presently preferred formof the invention, but is intended to be illustrative rather thandefinitive thereof.

Iclaim:

l. A switch construction comprising a casing; a body mounted in saidcasing for back and forth rocking movements about an axis between twoextreme positions; contact carrier. means coupled to said body formovements between first and second positions in response to back andforth rocking movement of said body; reciprocable operating meansmovable on sequential strokes from and to a normal position; firstindexing means on said body; and second indexing means on said operatingmeans and straddling said body, said first and second indexing meansbeing operable in response to movement of said operating means to saidnonnal position to rock said body from either extreme position to theother.

2. The construction set forth in claim 1, including spring means actingon said body for yieldably maintaining the latter in either of saidextreme positions.

3. The construction set forthin claim 2 wherein said spring means actson said operating means and biases the latter to said normal position.

4. The construction set forth in claim 1, wherein said first indexingmeans comprises a slide carried by said body and said second indexingmeans comprises a pair of arms carried by said operating means, each ofsaid arms having drive means for engaging said slide and applying aforce thereto sufficient to rock said body from one extreme positiontoward the other.

5. The construction set forth in claim 4 including spring means actingon said slide and urging it toward a position for engagement by aselected one of said drive means.

6. The construction set forth in claim 1, wherein said casing has anopen side adjacent said carriermeans.

7. The construction set forth in claim 6 including means carried by saidcasing for mounting the latter on a base with said open side and saidcarrier confronting said base.

8. A switch construction comprising contact carrier means movable alonga path between first and second positions; actuating means rockablebetween two extreme positions; means coupling said actuating means tosaid carrier means for moving the latter from one of its positions tothe other in response to rocking movement of said actuating means;reciprocable operating means straddling said actuating means and movablebetween first and second positions; and cooperable indexing means onsaid operating means and said actuating means engageable with each otherin response to movement of said operating means from said first positionto said second position, said indexing means being operable when engagedto rock said actuating means from one of its said positions to the otherin response to movement of said operating means from said secondposition toward said first position.

9. The construction set forth in claim 8 including spring means biasingsaid operating means to said first position.

10. The construction set forth in claim 8 including spring meansoperable yieldably to maintain said actuating means in either of itssaid extreme positions.

11. The construction set forth in claim 8 including means for limitingmovement of said actuating means beyond its extreme positions.

12. The construction set forth in claim 8 including spring meansoperable yieldably to maintain said carrier means in either of its saidpositions.

13. The construction set forth in claim 8 wherein said indexing meanscomprises a slide member slideably supported by said actuating means forsliding movements relative thereto.

14. The construction set forth in claim 13 including spring means actingon said slide member and yieldably maintaining the latter in a selectedposition relative to said actuating means.

15. The construction set forth in claim 14 wherein said spring means isoperable to shift said slide member from said selected position toanother position in response to movement of said actuating means fromone of its said positions to the other. v

16. The construction set forth in claim 15 wherein said slide memberprojects beyond one side of said actuating means in one extreme positionof said actuating means and projects ing said casing on a support havingconductive means confronting said carrier means through said open side.

19. The construction set forth in claim 18 wherein said mounting meanscomprises flexible extensions of said casing terminating in barbed endsaccommodated in openings in said support.

1. A switch construction comprising a casing; a body mounted in saidcasing for back and forth rocking movements about an axis between twoextreme positions; contact carrier means coupled to said body formovements between first and second positions in response to back andforth rocking movement of said body; reciprocable operating meansmovable on sequential strokes from and to a normal position; firstindexing means on said body; and second indexing means on said operatingmeans and straddling said body, said first and second indexing meansbeing operable in response to movement of said operating means to saidnormal position to rock said body from either extreme position to theother.
 2. The construction set forth in claim 1, including spring meansacting on said body for yieldably maintaining the latter in either ofsaid extreme positions.
 3. The construction set forth in claim 2 whereinsaid spring means acts on said operating means and biases the latter tosaid normal position.
 4. The construction set forth in claim 1, whereinsaid first indexing means comprises a slide carried by said body andsaid second indexing means comprises a pair of arms carried by saidoperating means, each of said arms having drive means for engaging saidslide and applying a force thereto sufficient to rock said body from oneextreme position toward the other.
 5. The construction set forth inclaim 4 including spring means acting on said slide and urging it towarda position for engagement by a selected one of said drive means.
 6. Theconstruction set forth in claim 1, wherein said casing has an open sideadjacent said carrier means.
 7. The construction set forth in claim 6including means carried by said casing for mounting the latter on a basewith said open side and said carrier confronting said base.
 8. A switchconstruction comprising contact carrier means movable along a pathbetween first and second positions; actuating means rockable between twoextreme positions; means coupling said actuating means to said carriermeans for moving the latter from one of its positions to the other inresponse to rocking movement of said actuating means; reciprocableoperating means straddling said actuating means and movable betweenfirst and second positions; and cooperable indexing means on saidoperating means and said actuating means engageable with each other inresponse to movement of said operating means from said first position tosaid second position, said indexing means being operable when engaged torock said actuating means from one of its said positions to the other inresponse to movement of said operating means from said second positiontoward said first position.
 9. The construction set forth in claim 8including spring means biasing said operating means to said firstposition.
 10. The construction set forth in claim 8 including springmeans operable yieldably to maintain said actuating means in either ofits said extreme positions.
 11. The construction set forth in claim 8including means for limiting movement of said actuating means beyond itsextreme positions.
 12. The construction set forth in claim 8 includingspring means operable yieldably to maintain said carrier means in eitherof its said positions.
 13. The construction set forth in claim 8 whereinsaid indexing means comprises a slide member slideably supported by saidactuating means for sliding movements relative thereto.
 14. Theconstruction set forth in claim 13 including spring means acting on saidslide member and yieldably maintaining the latter in a selected positionrelative to said actuating means.
 15. The construction set forth inclaim 14 wherein said spring means is operable to shift said slidemember from said selected position to another position in response tomovement of said actuating means from one of its said positions to theother.
 16. The construction set forth in claim 15 wherein said slidemember projects beyond one side of said actuating means in one extremeposition of said actuating means and projects beyond the opposite sideof said actuating means in the other extreme position thereof.
 17. Theconstruction set forth in claim 8 wherein said coupling means includes alost motion connection between said actuating means and said carriermeans.
 18. The construction set forth in claim 8 including a casing inwhich said carrier means is mounted, said casing having an open sideadjacent said carrier means; and means for mounting said casing on asupport having conductive means confronting said carrier means throughsaid open side.
 19. The construction set forth in claim 18 wherein saidmounting means comprises flexible extensions of said casing terminatingin barbed ends accommodated in openings in said support.